In 1995, Professor Chou et al. of current Princeton University proposed a new technology called nano-imprint lithography (Patent Document 1). The nano-imprint lithography is a technology including bringing a mold having a certain pattern in contact with a substrate on which a resin film is formed, pressurizing the resin film, and using heat or light as external stimulus for curing to form a target pattern on the cured resin film. This nano-imprint lithography has advantages that nano-scale processing can be easily and inexpensively carried out as compared with photo-lithography in conventional semiconductor device production.
Therefore, in place of the photo-lithography, the nano-imprint lithography is a technology expected for applications in a semiconductor device, an opto-device, a display, a memory medium, and a bio-chip etc. Thus, various curable compositions for photo-nano-imprint lithography used for nano-imprint lithography have been described (Patent Document 2 and Patent Document 3). Furthermore, Patent Document 4 describes a photo-imprint material including a compound having a silicone framework and a light polymerization initiator.
When a costly mold is used in the nano-imprint lithography, longer operating life is required for the mold. However, at the time of mold release, when force required for peeling off the cured resin film from the mold, that is, a peeling force at the time of mold release (hereinafter, abbreviated as “mold release force” in this specification) is large, the resin is easily attached to the mold and thus the mold tends to become unusable. Therefore, the material used for nano-imprint lithography (hereinafter called an “imprint material” in this specification) should require a low mold release force property (a property that the cured resin film is easily peeled off from the mold). In device production, heating processes such as baking and soldering may be carried out. In some cases, the film is exposed to a high temperature of about 260° C. in the heating processes. At this time, if the film has low heat resistance and thus decomposed materials from the film are sublimed, inside of devices and apparatus and equipment for producing the device are contaminated. This causes serious problems. Further, depending on the type of the device, the device may be used in a place where the device is exposed to heat. In such a case, a similar problem may also arise and thus high heat resistance is required for a structure produced as an optical member in a product such as a solid state imaging device, a solar cell, an LED device, a display, and the like.
However, although various materials have ever been described as imprint materials, a material that satisfies both low mold release force and heat resistance of not causing the sublimation of the decomposed compounds at a temperature of more than 200° C., for example at 260° C., has not been reported.